Feeder for tube-mills.



H. W. HARDINGE.

FEEDER FOR TUBE MILLS.

APPLICATION FILED MAY 11. 1916.

1,272,801. Patented July 16, 1918-. 2 16 an srarns PATENT orr w HARRY W. HARDINGE, OF NEW YORK, N. Y.

FEEDER FOB TUBE-MILLS.

naaaeoi.

' Specification of Letters Patent. Patented July 111$, 1931.8.

Application filed May 11, 1916. Serial No. 96,765.

in or disintegratingores and other materia s, particularly mills of the type known as tubemills or ballmills comprising a r0 tating barrel or drum having at the end of the axis on which the drum rotates-an inlet opening for the introduction of the ore? any convenient manner, as by means of screws passing through ears 19. This trough or other material. Such mills usually rotate on hollow axial trunnions, in which case itis customary to deliver the ore to the mill by means of a chute extending into one of the trunnions, the ore being accompanied by a stream of water when the mill is used for wet grinding. This method offeed is not altogether satisfactory, chiefly for the reason that the material backs up in the trunnion and overflows the same, so that the mill slobbers, thereby keeping the surroundings wet and necessitating frequent cleaning of the floor. Moreover, 'fine particles of the material work their wa into the trunnion bearings, causing rapi 'and destructive wear.

It is accordingly the object of my present invention to provide an improved feeding device, whereby the drawbacks mentioned will be obviated. To this and other ends the invention consists in the novel features of construction and combinations of elements hereinafterdescribed.

One form of the invention is illustrated in the accompanying drawing, in which Figurel is a side view of a ballmill of the conical type equipped with my improved feeder, the latter being shown in section on its axis of rotation.-

Fig. 2 is across section of the-feeder on the lane indicated by line 22 of Fig. 1.

Fig. 3 is a section on the plane indicated by line 33 of Fig. 2. I

Fig. 4 is a side view of a modlfication of the feeder shown in Figs. 1, 2 and'3, and Fig. 5 is an end view of the same. Y The mill 10 is provided with an inlet trunnion 11 and I an 7 outlet trunnion 12, mounted in bearings 13, and is rotated by any convenient means, not shown, through the agency of the large gear 14. The feeder 15 comprises a conical casing composed of two conical ortions or halves detachably joined at their bases andjiaving axial inlet and outlet openings 16, 17, respectively. Around the outlet opening is a flange by which it can be removably secured to the in let trunnion, as by means of screws or bolts as indicated in Fig. 3. 0n the inside of the inner conical portion of the feeder (that is, the' half next to the mill 10) isat least one open helical trough-conveyer 18, secured in extends from the periphery of the feeder to the axis thereof, followingthe inner surface, and opens into the trunnion 11 at the inlet opening 17 of the feeder.

The conveyer is distinctively an opentrough having, not merely an open frontor scoop-end (such as common to conveyors of the snail type) but an open top, the conical inner surface of the casing constituting the inner wall of the trough, and its outer wall being formed b .a longitudinal upri t flange over the trip or upper edge of with there. is free communication between the interior of the trough, and that portion of the feeder easing external to the trough, as indicated in Figs. 2 and 3. The result of the open-top-trough arrangement is that, during the rotary movement of the feeder, the material contained in the casing will be taken wall, as well as at its scoop-end, so long as the trough is moving-through the material; and, on the other hand, any surplus or ex cess of material thus taken will, as the trough rises above the level of the material in the casing, escape over the top of the said outer wall of the trough and drop back again to the bottom of the casing, thus assuring an even feed without danger of blocking or choking.

The ore or other material to be ground is discharged into the feeder through the inlet openin 16 by a chute 26 and falls to the bottom, w ere it is picked up by the trough into the trough over the top of its outer (the mill and feeder revolving in the direction of the arrow in Fig. 2), which acts in the manner of an Archimedean screw. It will be observed that the conveyer is not a spiral, but a conical helix, of helico-spiral form, beginning at or about the plane indlcated by the line 22 of Fig. 1 and terminating at the outer end of the. inlet trunnion 11. Accordingly the material transported by the conveyer not only is carried radially inward but also has a movement parallel to the axis of the mill, and hence it meets the trunnion at an obtuse angle to the axis instead of at a right angle. 'Moreover,

the bottom of the trough is preferably inmained in the trunnion. Also, if any material falls down out of an upper part of the trough as the feeder revolves it does not esdown the inclined (conical) wall of the feeder and into the part of the trough-which is immediately below; If the chute momentarily delivers more material than the conveyer can carry, the excess is not spilled out on the ground or floor but simply remains in the bottom of the feeder casing until the conveyer comes around again. Slobbering du to irregular rate of supply to the feeder is thus entirely eliminated if reasonable care is exercised to see that the supply is not so gast as to cause the feeder actually to overow. a a

If desired, a pi e 16 may be provided, extending through he inlet opening 16 into a suitable aperture 18 in the inner portion of the trough 18, for discharging a jet of water to aid the flow of material through the trunnion into the drum. In case of dry grinding, the pipe is used for an air jet. I may also provide a lip or flange 16 around the inlet opening 16, on the inside. i This lip receives the impact of the material discharged by the chute 26 and so protects the edge of the opening itself from wear, the lip being renewed when worn out. The lip also serves to prevent escape of material which, carried up by the ascending side of the casing, slides down the incline as it approaches the highest point of its travel.

Sometimes there is too much Water delivered W1th the ore or other material, and in order to get rid of the excess before it enters the drum the feeder casing may be provided with one or more circumferential series of escape apertures, as 15*. When a large proportlon of the water is to be removed, all the escape apertures are left open, so that only so much water "will be retained as can be held by the space below the lowermost aperture, the rest escaping through the open holes. 4 If more water is to be retained, the holes of the first series are closed, as by means of screw plugs 15". If all the water 5 the feeder is also provided with'external conveyer-arms or scoop-arms 22, bent spicape from the trough altogether. but slides rally in the direction of' rotation so as to scoop material from the vessel 23 in which the conveyer-arms dip. Material thus picked up is delivered into the feeder casing, and is there picked up by the conveyer-trough and 'delivered to the inlet trunnion of the mill, If niaterial is intentionally supplied to the vessel 23, the chute 20, Fig. 1, can be used or not, as desired. Or the vessel 23 can be used merel to catch material overflowing from the feeder by reason ofsupplying material thereto at too fast a rate.

is not limited to the embodiments herein specifically illustrated and described but can be embodied in other forms without departure from its spirit.

I claim:

1. The combination with a tube mill rota- It is to be understood that the invention table about its axis having an axial inlet opening, of a feeder comprising a rotaryhollow conical casing having an axial outlet communicating with said opening, and an open-top trough-conveyer of hellco-spiral form carried by the casing inside .of the same and following the conical inner surface of the casing from its periphe to its axial outlet, over the upper longitu inal edge of which conveyer there is free communication between the interior of the trough and the surrounding casing. v

2. The combinationwith a tube mill rotatable about its axis having an axial inlet opening, of a feeder comprismg a rotary hollow conical casing having an axial outlet communicating with said inlet opening, and an open-top trough-conveyer of helico-spiral form following theconical inner surface of the casing from its periphery to its axial outlet, the conical inner surface of the ca's-.

ner surface of the feeder constituting the insaid outlet to facilitate the discharge of the ner Wall of the trough and the outer Wall of material from the trough through the outlet, the trough consisting of a longitudinal and means for discharging a jet of Water or I flange over the upper edge of which there is air outwardly through the outlet opening.

5 free communication between the interior of In testimony whereof I hereunto affix my the trough and the surrounding casing, the signature. bottom of the conveyer being inclined at HARRY W. HARDINGE. 

